

Simple. We let them get away with it. Compare:
“Your PC is out of date” “Don’t be stupid, it’s only 2 years old and still works fine” with
“Your phone is out of date” “OK I’ll buy a new one”.
There needs to be a lot more of Answer A to Statement B.
The Norks Kims are world leaders and KC3 isn’t? Did I accidentally stumble into a .ml echo chamber?
On looking at the OP’s list I was also wondering why Trooping the Colour wasn’t on it, as it is a military parade for the (official) birthday of one of the leaders in the G7.
King Charles III is not symbolic; he is the ruler of the UK and the Commonwealth. He refers to Parliament as “my government” in his speeches and no new laws can be passed without his approval (Royal assent). He is the head of the military and the Church. So referring to Charles as a symbolic figurehead is factually inaccurate. Deferring power to Parliament doesn’t change that. Taking it up again may cause a constitutional crisis, but I believe it is an option.
This seems like a fairly reliable source, on the grounds that although it’s “only” a blog, solicitors aren’t known for posting misinformation. https://www.milnerslaw.co.uk/could-king-charles-iii-dissolve-parliament/